Eunkoo Yun

Experimental and Thermoeconomic Analysis of Small-Scale Solar Organic Rankine Cycle (SORC) System

A small-scale solar organic Rankine cycle (ORC) is a promising renewable energy-driven power generation technology that can be used in the rural areas of developing countries. A prototype was developed and tested for its performance characteristics under a range of solar source temperatures. The solar ORC system power output was calculated based on the thermal and solar collector efficiency. The maximum solar power output was observed in April. The solar ORC unit power output ranged from 0.4 kW to 1.38 kW during the year. The highest power output was obtained when the expander inlet pressure was 13 bar and the solar source temperature was 120 °C. The area of the collector for the investigation was calculated based on the meteorological conditions of Busan City (South Korea). In the second part, economic and thermoeconomic analyses were carried out to determine the cost of energy per kWh from the solar ORC. The selling price of electricity generation was found to be

Development of Small-scale Organic Rankine Cycle System and Study on its Operating Characteristics

0.68/kWh and

Development and Characterization of Small-Scale ORC System Using Scroll Expander

0.39/kWh for the prototype and low cost solar ORC, respectively. The sensitivity analysis was carried out in order to find the influencing economic parameters for the change in NPV. Finally, the sustainability index was calculated to assess the sustainable development of the solar ORC system.

Design and Thermodynamic Analysis of Hybrid Tri-generation Gas Engine-Organic Rankine Cycle

KeyWords: Organic Rankine Cycle(유기랭킨사이클), Scroll Expander(스크롤팽창기), Thermal Efficiency(열효율), Isentropic Efficiency(등엔트로피효율)초록: 본연구에서는소형저온유기랭킨사이클시스템의작동특성을파악하기위하여R-245fa를작동유체로사용한소형ORC 발전시스템을설계및제작하였고, 다양한저온의열원온도에대한실험적연구를수행하였다. 저온열원을모사하기위하여최고150 °C의물을공급할수있는110 kW급의전기저항히터를제작하였으며, 컨트롤러를통해서다양한열원온도및유량조건에대한실험이가능하도록구성하였다. 또한, 상용공기용스크롤압축기를이용하여팽창기로개조하고동력계및동기식모터와직접연결하였다. 로드뱅크및PI 제어방식을사용하여팽창기의회전속도에따른동일열원온도조건에대한실험을각각수행하였으며, 소형ORC 시스템의성능에영향을미치는다양한인자들에 대하여분석하고논의하였다.Abstract: Experiments were conducted to determine the operating characteristics of a small-scale ORC (organicRankine cycle) system for various low-temperature heat sources. A small-scale ORC power generation systemadopting R-245fa as a working fluid was designed and manufactured. Hot water was used as the heat source,and the temperature was controlled using 110-kW electric resistance heaters that provided temperatures of upto 150 °C. An open-drive oil-free scroll expander directly connected to a synchronous generator was installedin the ORC unit. Experiments were conducted by varying the rotational speed of the expander under thesame heat source temperature conditions. The factors that influence the performance of the small-scale ORCsystem were analyzed and discussed.

Experimental investigation of an organic Rankine cycle with multiple expanders used in parallel

In order to determine the operating characteristics of a small-scale ORC (organic Rankine cycle) system for various low temperature heat sources, experiments were carried out. A small-scale ORC power generation system adopting R-245fa as a working fluid was designed and manufactured. Hot water was used for the heat source and the temperature was controlled by the 110 kW electric resistance heaters which provided up to 150 °C. Cooling temperature was controlled by a circulating water chiller to simulate various heat sink environments. An open-drive oil-free scroll expander directly connected to a high-speed synchronous generator was installed in the ORC unit. The efficiencies of the cycle and the expander, electric power of the developed ORC system with respect to the operating conditions were investigated by experiments. The factors which influence the performance of the oil-free scroll expander were analyzed and discussed.

Experimental study of a 1 kw organic Rankine cycle with a zeotropic mixture of R245fa/R134a

Abstract >> In a gas engine, the exhaust and the engine cooling water are generated. The engine cooling water temperature is 100 ℃ and the exhaust temperature is 500 ℃. The amount of heat of engine cooling water is43 kW and the amount of heat of exhaust is 21 kW. Eight different hybrid organic Rankine cycle (ORC) systemconfigurations which considering different amount and temperature of waste heat are proposed for two gas enginetri-generation system and are thermodynamically analyzed. Simple system which concentrating two different wasteheat on relatively low temperature engine cooling water shows highest thermal efficiency of 7.84% with pressureratio of 3.67 and shaft power of 5.17 kW. Key words : Gas engine(가스 엔진), Engine exhaust(엔진 배기), Organic Rankine cycle(유기랭킨사이클), Hybridsystem(하이브리드 시스템), Thermodynamic analysis(열역학적 분석) † Corresponding author : kckim@pusan.ac.kr Received : 2015.01.02 in revised form 2015.01.24 Accepted: 2015.02.28Copyright ⓒ 2015 KHNES Nomenclature h : enthalpy (kJ/kg)η : efficiency